The present invention relates to an actuating arrangement with at least one actuating member mounted in a carrier that is movable between operating and non-operating positions and in particular to an interlock to prevent unintended actuation when the carrier is in the non-operating position.
GB 1 474 862 discloses an actuating arrangement for a front end loader of an agricultural tractor. The actuating arrangement contains a handgrip that is connected by a cable to the tool of the front end loader. The actuating arrangement is arranged on the upper end of a vertically pivoted mount, that can be brought into an operating position and a non-operating position.
The prospectus BAAS TRIMA front loader, printer""s notation BandT 5.000 shows on its page 5 a lifting control for a front loader, that is provided with a safety control circuit. This safety control circuit can be activated by means of a small lever and blocks the control.
The problem underlying the invention is seen in the fact that the actuating arrangement is not sufficiently protected against an inadvertent operation, in particular in the non-operating position of the carrier or mount, and that a vehicle with a lifting and loading arrangement can bring about a dangerous situation upon an unintended actuation.
The problem is solved according to the invention by the provision of an interlock that prevents movement of the carrier to the non-operating position as long as it is still possible to activate the actuating members. An activation can be performed, for example, by mechanically depressing a component, but also by a contacting or non-contacting switching process. Accordingly, on the one hand, on the basis of the position of the carrier, it is visibly obvious whether an actuation is possible or not, and an unintended movement of the carrier into a position in which the actuating arrangement cannot be controlled visually or can be operated improperly is prevented. A position in which an activation of the actuating arrangement should not be possible may be a non-operating position as well as any position of the carrier outside of the operating position which can create more freedom of movement for an operator, free space for a pivoted operator""s seat, space for other components or the like, or space for ingress and egress.
A simple and reliable means of preventing the movement of the carrier or an activation of the actuating arrangement, is seen in the application of a mechanical locking bar that can be brought into engagement with the actuating member or members or the interlock. The selective engagement possibility gives the assurance that either the repositioning of the carrier or of the interlock is possiblexe2x80x94but in no case that of both.
The locking bar can also be operated electrically by means of an electromagnet or the like, and is then in a position to block the interlock or the actuating arrangement, when each of the other components can be moved or actuated.
The interlock can be configured mechanically and therefore very robustly. On the other hand an electrical interlock makes sense where space conditions do not permit a simple guide arrangement of a mechanical linkage or an interconnection with further signals is to be provided.
A mechanical interlock can be provided simply and cost effectively by means of a rod or a tensioning device, for example, a cable. The corresponding position of the interlock that should result from a relative change in the position of the carrier with respect to a stationary bearing is brought about by the eccentric location of the mechanical interlock with respect to the pivot axis of the carrier. The location of the interlock can be varied by variation in the degree of eccentricity.
The use of an actuating member that can be varied in length or moved linearly with corresponding recesses makes possible a simple engagement or disengagement of the locking arrangement or the locking bar, and thereby performs an interlock or disengages it. Here positive locking is attained simply by movement of the locking bar transverse to the actuating member.
The application of such an advantageous actuating arrangement provides great utility for a vehicle equipped with a lifting or loading arrangement, since such arrangements in a vehicle can present a danger with inexpert handling. These vehicles can be agricultural or forest products vehicles, but also vehicles in the construction trades. Therefore the tensioning or loading arrangement can include three-point hydraulic devices, loader shovels, front hydraulic devices, grippers and the like.
The actuating arrangement is particularly advantageous on an agricultural tractor with a front end loader, since the latter is used only briefly, but remains attached to the agricultural tractor in the non-operating condition.